Inner tube



H. M. DODGE. INNER TUBE.

APPLICATION FILEDv SEPT. 11, 1920 $HEETS-SHEET I H. M. DODGE INNER TUBE.

APPLICATION FILED SEPT. I l, 1920.

1,414,333 Patented 25,1922.

UNITED. STATES- PATENT OFFICE;

HOWARD M. DODG E, OF AKRON, OHIO, ASSIGNOR TO ERNEST F. MAROHA, OF CLEVE- LAND, OHIO,

nmna runs.

,lpplication filed September 11, 1920. Serial'No'. 409,726.

To all whom it may concern:

Be 'it known that I, HOWARD M. DODGE, a

- citizen of the United States, and resident 'of Akron, in the county of Summit and State of Ohio,have invented certain new anduse- I hereby declare the following to be a full, clear, and exact description, such as will enable others skilled in the art to which'it appertains to make and use'the same. i

The objects of the invention are to provide an improved inner tube for a pneumatic tire, which is so constructed as to resist leakage when punctured and is also so constructed as to resist collapse when deflated, thus making the tube more durable, eflicient and prac-.

tical for general use.

The invention comprises an inner tube corrugated or fluted throughout substantially the greater part of its longer circumferential surfaces, and molded to assume a smaller diameter than that of the inner circumference of the casing, and after it has I is removed and the tire will retain its ability.

been inflated therein it assumes the full diameter of the inner surface of the casing, with the outwardly projecting flutes or ribs engaging with the inner circumference ofv the casing.

When the inner tube is subjected to further internal pressure the inwardly projecting ribs or flutes will be flattened down and the material composing them will be subjected to compression laterally or in the direction of the short circumference of the-tube and the material will be condensed so that'when punctured by a sharp object,,such as a nail or spike, it will close as soon as the object 1 to retain air under pressure, without leakage.

The invention also includesthe rectangular recesses formed between the external flutes orribs of the inner tube by'means of transverse, externally, projecting ribs (preferably hollow). When the longitudinal and transverse projections thus formed are compressed against the casing a partial vacuum will be created between them, which-resists deflation of the tube and prevents thetube from shifting irregularly about in the casing, andincreases its efficiency and dura-- form.

bility.

The invention is illustrated in the accom panying drawings, hereinafter-further described, and specifically pointed outinfth'e v lateral pressure at the e ges of the rim side ful Improvements in Inner Tubes, of which portion of the inner 'tube;.Fig. 3 is a longitudinal section thereof; Figs. 4, '5, 6, and 7 showmodified forms of-construction of the inner tube. j

-In these views, A represents the casing;

- B represents the inner tube, which, when deflated, is oil smaller diameter than that of the circumference of the inner'surface, C,

' of the casing.

The inner tube is longitudinally fluted or corrugated on both inner and outer surfaces, the thickness of the material remaining substantially the same throughout to prevent irregular compression thereof when the tube is inflated.

These corrugations preferably extend around the greater part of the transverse circumference of the tube, a-small portion being left smooth at D, where: it comes'in contact with the filler piece, E, which closes the gap between the rim edges of the casing.

V The corrugations are equally spaced aboutthe periphery of thetube. and are not deeply j indented but form alternate longitudinal an-' nular grooves, F, and longitudinal annular projections, G the material embodied there'- in having such an amount of totalv superficial area that when expanded under internal pressure from the collapsed-condition the inner tube will exactly correspond "in;

diameter with the inner'circumference of the casing, with the outwardly projecting flutes or ribs in contact with the casing and I00 the inwardly projecting corrugations or;

flutes extending more nearly to theirjffnif;

width, but .still preserving theirfarcnatie Upon the. furtherapplication t internal pressure the inwardly extending corrugapressed air contained therein.

It is also much less susceptible to puncture when compressed in this manner than if it were stretched tightly by inflation in the ordinary manner.

Transverse corrugations or hollow ribs H connecting the longitudinal ribs also provide the same useful result, and when expanded make contact with the inner surface of the casing.

Further, when subjected to expansion the arched material lying between these ribs will become flattened and upon further inflation of the tubes will be compressed longitudinally of the tube and condensed in the same manner as the circumferential ribs previously described. This action subjects the material to compression in two directions, both laterally and longitudinally, and thickens it to a certain extent at all points of'the corrugated surfaces.

An important advantage obtained from the rectangular recesses thus formed in the outer surface of the inner tube is found in the fact that when the tube is flattened against the casing a partial vacuum will be produced at the position of each recess, which will have a tendency to grip the casing and to resist deflation of the tube.

Also, the transverse ribs and yacuum producing depressions will have a tendency to prevent longitudinal or other shifting of the tube within the casing.

At I, Fig. 1, are shown longitudinal flutings which are positioned closely adjacent to the rim edges, J, J, of the outer casing. These flutings, when expanded and afterwards compressed against thesides of the filler piece and bead or rim ed es of the 4 casing, force these edges into suc close engagement with the flanges, K, K, of the rim that the danger of their becoming detached therefrom is reduced to the minimum. The central portion of the filler piece, E, is also pressed tightly into the space between the rim edges of the casing by the narrow uncorrugated portion, D, of the inner tube.

In Fig. 4, the transverse flutings, H, are shown opposite but diagonal; in Fig. 5, they are staggered; in Fig. 6, transverse flutings, H, are joined by longitudinal flutings, Gr and H, and in Fig. 7 the longitudinal flutings, G, are formed in sinuous lines, and are joined by spaced, transverse flutings H.

Other variations in the combination and arrangement of the flutings can be arranged within the scope of the claims.

Having described the invention what I claim as new and desire ,to secure by Letters Patent is: 4

1. The combination with,a casing, of a pneumatic inner tube therefor,-said tube provided with annular longitudinally directed hollow flutes alternating with annular recesses, and also provided with .transverse hollow ribs connecting adjacent flutes across said recesses, the recesses included between said flutes and ribs, forming vacuum chambers in contact with the inner surface of said casing when said tube is fully inflated.

2. The combination with a casing, of a pneumatic tube therein, said tube provided with longitudinally directed annular pro-- jections alternating with annular recesses on both inner and outer surfaces, and With narrow, staggered, transverse, hollow projections connecting adjacent longitudinal projections on their outer surfaces, and provided with a narrow, smooth, annular, projecting surface upon the rim side, the normal diameter of said tube being less than the normal diameter of the inner surface of said casing, said longitudinal and transverse projections enclosing vacuum producing surfaces when said tube is inflated into contact with the inner surface of said casing.

3. The combination with a casing of a pneumatic tube therefor, said tube provided with annular longitudinally directed hollow fiated wedges apart therim edges of the casing.

4. The combinatlon of a casing adapted to be mounted on a rim with the space between therim edges of thecasing narrowing towards the rim, of a pneumatic tube having a normal diameter less than the internal diameter of the casing, the tube being-normally corrugated so that its external surface is greater than the internal surface of the casing, and the tube having a rim side normally straight in cross section for a distance greater than the distance between the rim edges of the casing, whereby when the tube is inflated and the corrugations smoothed out against the casing, the tube walls will be under lateral compression and the flat rim side will wedge apart the rim edges of the casing.

5. The combination of a casing adapted to be mounted on a rim, a filler adapted to lie against the rim between the rim edges of the casing and having flaps lying against said rim, edges of the casing, the flaps detheir outer edges, whereby when the tube is creasing in thickness as they recede from the inflated Within the casing its walls are under rim, and a pneumatic tube having a normal lateral compression and the rim side is diameter less than the internal diameter of wedges out against the flaps of the filler.

5 the casing, a normal outer surface greater In testimony whereof, I hereunto set my 15 than the inner surface of the casing, and a hand this 2" day of Sept. 1920.

rim side normally straight in cross section HOWARD M. DODGE. for a distance greater than the distance be- In presence of v tween the flaps of the filler at the rim and WM. M. MONROE,

10 less than the distance between the'flaps at t CHAS. C. GoLDMAN. 

